Microfluidic technology and other techniques may be employed to measure various types of physiologic parameters that might be important to diagnose or manage a disease.
Generally, the term “microfluidics” refers to the art making very small channels using microlithographic and microfabrication techniques. For example, a substrate such as glass with polymers may be used to make channels. Other substances used in formulating substrates include, for example, silicon and aluminum. Various other types of substrates are possible. The channels may be fabricated using various techniques, e.g., by etching silicon using a deep reactive ion etch with a mask that provides precise control of geometry. Various patterns may be employed, e.g., curved lines, straight lines, etc.
Microfluidics may be used, inter alia, to perform a function such as ion chromatography or liquid chromatography to look for and measure an ion or molecule. A typical application in an ion chromatograph is introduction of a small sample liquid in a column of fluid that is otherwise neutral. Introduction, for example, may be achieved via various fluid introduction components, e.g., a pump, a microsuction component, etc.
The sample moves through the column. In some examples, a field, e.g., an electric field, is applied across the column which affects the diffusion times of the ions of the sample as the ions move through the column. The ions are detected, e.g., at the end of the column. A time of injection of the ions of the sample can be calculated based on detection, diffusion rates, and the dimensions of the column.
Information may be obtained in various ways, e.g., based on measuring electroconnectivity. In various aspects, channels are filled with different materials that modify the motion rates of different ions.
Such diagnosis or disease management by means of a microfluidic approach would be helpful if it could be done conveniently and in conjunction with other processes that might already be taking place for other reasons.